1. Synthesis, Thermal and Photochemical Reactivity of Highly Conjugated Arenediynes
John D. Spence, Department of Chemistry, California State University Sacramento, 6000 J Street, Sacramento, CA 95819
Several highly conjugated arenediynes have been prepared to examine the effect of extended conjugation on thermal and photochemical enediyne reactivity. Examples include a series of naphthylethynyl arenediynes, 1,2-bis(4-phenylbuta-1,3-diynyl)benzene, and 1-ethynyl-2-(4-phenylbuta-1,3-diynyl)benzene. From our naphthylethynyl series, naphthalen-2-ylethynyl arenediyne was found to undergo traditional C1-C6 Bergman cyclization upon irradiation at 300 nm while naphthalen-1-ylethynyl arenediyne undergoes a tandem 2+2 photocyclization (illustrated below) at 350 nm. Introduction of methoxy substituents on the naphthalene ring appear to increase overall reaction yields.